The District will pony up $1.5 million to build out a Nationals Park retail space for a nonprofit sustainability showroom and learning center.

Christophe Tulou, executive director of the D.C. Department of the Environment, said Greenspace NCR (formerly GreenHome) will serve as a “third-party convener” to bring environmental sustainability, efficiency and affordability to the masses, a mission the city itself is ramping up with a few initiatives of its own.

“It’s sort of a neutral space where we can bring people together, where the Greenspace folks themselves can bring people in to figure out how they get this job done,” Tulou said.

Once estimated as a $2 million project, the Greenspace build-out cost is now closer to $4 million. When the plans were announced last June, there was no suggestion that the District would ultimately contribute much to the construction price tag.

But Greenspace Executive Director Patty Rose said the cost of infrastructure work has risen significantly, and D.C., which owns Nationals Park, is coming through with the additional money.

Rose said she and DDOE must establish a funding agreement before she can estimate a time frame for the project’s completion.

“Largely, the mayor has this wonderful sustainability plan the administration is developing with the community,” Rose said. “This space will be a learning and resource center to more fully implement the plan when it’s done.”

As the District prepares to invest in the 12,000-square-foot Greenspace center, designed to meet the Leadership in Energy and Environmental Design Platinum standard, it is simultaneously planning the launch of the Property Assessed Clean Energy (PACE) program while also soliciting a contractor to draft the latest edition of D.C.’s Comprehensive Energy Plan.

Officials credit Mayor Vincent Gray’s focus on green, notably his Vision for a Sustainable D.C., for the near-simultaneous rollout of those programs.

Greenspace and PACE have been around for some time — the ideas emerged during Mayor Adrian Fenty’s administration — but a lack of funding and changes in federal law slowed the process.

“In order to get to the goals the mayor has articulated in his Sustainable D.C. Vision, it’s clear to us that we’re going to have to do lots more,” Tulou said. “Energy efficiency is a no-brainer so long as the cost you invest is not so much greater than the benefit you get in terms of lower utility bills.”

Greenspace has raised more than a $1 million for its cause, much of it in furniture and fixture donations, Rose said. The space, she said, is a “cold, dark shell right now.”

In one part, there’s nothing but gravel — the concrete floor was never installed.

“There’s no plumbing,” Rose said. “There’s nothing in the space. There’s no electricity, fixtures. There’s no nothing. That was part of the challenge in terms of build-out, and it made it more expensive.”

Gray has proposed shifting $1.5 million in capital funds to DDOE, where it will be divvied up for Greenspace construction, likely in coordination with the Department of General Services. The shift in funds is undergoing a standard D.C. Council review but is expected to survive.

At the same time that D.C. is assisting in the development of a sustainability showroom, it is also plotting a program to help commercial property owners put those green ideas into practice. The “built environment” in the District is responsible for an estimated 75 percent of the city’s greenhouse gas emissions, Tulou said.

Through the PACE program, commercial property owners will be able to borrow money for energy-efficiency improvements and pay it back through their semiannual property tax bills.

The D.C. Council agreed in 2010 to finance as much as $250 million in PACE bonds, which will be purchased by private banks and then lent to property owners. Tulou said he hopes to close on the first project this fall, and lend $50 million to $70 million in the next couple of years.

“That’s scratching the surface,” he said. “We know how this would work, and really we’re down to negotiating with parties to make sure frankly everybody’s comfortable with it.”

DDOE will bring all these green pieces together in its Comprehensive Energy Plan — the subject of a current contracting solicitation, with sealed offers due by July 13.

The plan will establish a comprehensive set of energy efficiency goals and strategies “that will put the city on a path to reducing energy consumption, increasing local generation and clean power usage, ensuring energy reliability and affordability, and creating of green jobs for District residents.”

Roughly 80 percent of the city’s energy comes from fossil fuels, and 8 percent from renewable sources. D.C. has set a goal of reducing greenhouse gas emissions 80 percent by 2050.

This energy plan will be the District’s fourth and most detailed, building on all previous plans.

It will delve into energy the consumption patterns and trends, the marketability of energy efficiency, the potential for renewable energy development, transportation strategies, energy outreach and awareness, green affordable housing production — and the challenges of meeting those goals.

“I think this time is particularly significant because it falls in place at the same time we we’re creating this broader, sustainable strategy,” Tulou said. “What it does is become much more important in informing that process.”